Tom Jones has spent a good portion of his career not being able to tell his family what he does at work. He recalls sitting at the dinner table one night 30-plus years ago, unable to share with his spouse that, just hours earlier, he was read into a classified military project. In the years that passed, Jones said, he's grown used to not being able to provide details of what he does every day.

"I've been not able to talk about what I do at work for so much of my career, I guess I don't even really think about it that much anymore," he said during an interview last week.